|Publication number||US7216463 B2|
|Application number||US 10/726,205|
|Publication date||May 15, 2007|
|Filing date||Dec 1, 2003|
|Priority date||Oct 1, 1999|
|Also published as||CA2385136A1, CA2385136C, EP1224431A2, EP1224431A4, US6655102, US7836661, US20040134138, US20070144109, WO2001025715A2, WO2001025715A3|
|Publication number||10726205, 726205, US 7216463 B2, US 7216463B2, US-B2-7216463, US7216463 B2, US7216463B2|
|Inventors||John L. LaRue|
|Original Assignee||Larue John L|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (38), Classifications (18), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a divisional of U.S. application Ser. No. 09/676,878 filed Sep. 29, 2000, now U.S. Pat. No. 6,655,102 and incorporated by reference herein.
The present invention relates generally to the field of camouflage. More particularly, the present invention is directed to a camouflaged structure and a method of camouflaging a structure against a background having a generally uniform composition.
Skylines are becoming less visually attractive due to the addition of tall structures that are not visually integrated into their surroundings and therefore stand out against their backgrounds, which frequently includes the sky. For example, with the continuing proliferation of mobile communications devices such as cellular telephones, personal digital assistants (PDAs), pagers, text messaging devices and the like, mobile communications service providers are constructing more and more antenna facilities, including cell towers, to improve the quality of existing services, increase the variety of services offered and increase the coverage area of their services. Thus, service providers are not only adding more cell towers to urban and suburban regions where cell towers already exist, they are constructing new towers in regions where no facilities had existed. In addition, a service region may have more than one service providers, each having its own cell towers separate from the cell tower(s) of the other service provider(s).
To optimize a cell tower's coverage area, the cell tower should generally have its antenna(s) located high above the ground and at a location unobstructed by adjacent objects, such as buildings, trees and mountains, among others. To achieve this goal, cell towers typically extend above the highest features within their respective coverage area. Since cell towers generally extend above most or all of surrounding objects, viewers typically view these structures against a background sky.
Until relatively recently, service providers made no attempts to lessen the visual impact of their cell towers, other than perhaps painting them a with a light-color paint, such as a neutral gray. However, due to the large number of cell towers being constructed and increased concern over the aesthetic impact of these cell towers, more and more communities are banning cell towers within their jurisdictions. In response, service providers are attempting to make their cell towers more attractive, e.g., by disguising, or camouflaging, them as other objects, such as trees and cactuses. The realism of such disguises, however, has generally been less than desirable because the cell towers are typically significantly larger than typical simulated object and the geometrical requirements of the cell towers are not suited to simulating such objects.
Other conventional visual camouflaging techniques are generally not suitable for reducing the visual impact of cell site antennas and support towers. Conventional visual camouflaging techniques are generally one of two types. The first type is used when the environment surrounding an object to be visually concealed is non-uniform, i.e., contains a plurality of juxtaposed regions that visually contrast with one another to form repeating patterns, random patterns or a combination of repeating and random patterns. Such patterns are found in, e.g., cityscapes, landscapes and seascapes, which are generally viewed horizontally, and aerial views of natural and manmade features on the surface of the earth. In this type of camouflage, the goal is provide a pattern, or image, that simulates a pattern contained in the background against which a structure is viewed between a viewer and the structure so that the viewer confuses the simulated pattern with the background pattern and thus cannot readily distinguish the outline and/or other features of the structure from the background.
Examples of pattern camouflaging include U.S. Pat. No. 1,305,296 to MacKay and U.S. Pat. No. 2,292,848 to Robson. Each of these patents discloses a technique of painting a ship with various patterns comprising discrete regions of certain colors. In MacKay, the pattern is designed to simulate a seascape. In Robson, the pattern provides a compromise between concealment against a seascape and deceiving an observer as to attributes, such as size, shape, speed and direction of travel, of the ship once the ship has been spotted. Creating patterns from discrete regions of different colors is not suitable for concealing a structure against a generally uniform background such as the sky.
Examples of image camouflaging include U.S. Pat. No. 5,142,833 to Svehaug, U.S. Pat. No. 5,373,863 to Prizio and U.S. Pat. No. 5,220,631 to Grippin. Svehaug discloses a camouflage screen comprising a panel for placing between a user and an observer. The panel has a planar reflective surface that, when properly positioned, generally faces and is slanted toward the observer so that the user is concealed behind the panel and an image of the terrain below the slanted panel is reflected to the observer. Prizio discloses a camouflage blind for placing between one or more users and an observer. The blind comprises a plurality of panels pivotably attached to one another along adjacent edges so that the blind can be easily stored, transported and set up in the field. Each of the panels includes a planar reflective surface that, when properly positioned, generally faces the observer and reflects to the observer an image of one or more objects contained in the foreground of the reflective surface. The devices of Svehaug and Prizio are not suitable for being mounted on a structure, such as a cell tower.
Grippin discloses a camouflage device that uses optic fiber cables to conceal an object by transferring an image of the background (as viewed by a viewer) of the object to the foreground of the object. The device comprises a plurality of background imaging lenses, a plurality of foreground imaging lenses and a plurality of optic fibers that each connect a background imaging lens to a corresponding foreground imaging lens. The background imaging lens creates an image of the background that is transferred to the foreground imaging lens via the corresponding optic fiber. The foreground lens then forms an image of the background that is viewed by the viewer in the foreground of the device. Due to the necessity for optical quality lenses and the complexity of this device, it is not a practical option for camouflaging a large structure, such as a cell site antenna support tower. In addition, this device would be difficult, if not impossible, to adapt to provide such images for a full 360° around a structure.
The second type of camouflaging technique is used to conceal an object against a background having a generally uniform composition of hue, saturation and brightness, wherein the object subtends a small arc of view. An example of this technique is U.S. Pat. No. 4,611,524 to Ferris, which discloses a camouflaged vehicle, such as an aircraft, surface vehicle or the like, at least a portion of which remains undetected until the vehicle subtends an arc of substantially five minutes when used against at least one predetermined light background reflectivity. One surface of the vehicle includes a substantial area of a predetermined reflectance that matches the reflectance of the predetermined light background. The area includes at least three defined portions, at least two of the portions having different reflectance so that when the reflectance of one of the defined portions is added to the total reflectance of the others of the three defined portions and the results averaged, they will have a reflectance substantially that of the predetermined light background. A limitation of this technique is that it is only suitable for objects subtending small arcs of view. Thus, this technique is not effective for large objects, such as cell site support towers, that are frequently viewed at a subtended arc of much greater than five minutes. In addition, this technique is not suitable when the foreground is brighter than the background.
In view of the foregoing, there is a need for a camouflaging technique that is economical and is capable of providing a large structure, such as a cell tower, with reduced visibility against a background, such as the sky, having a generally uniform composition of hue, saturation and brightness.
In a first aspect, the present invention is directed to a method of camouflaging a surface of a structure against a background containing a first color and a second color simultaneously or at different times. The method includes coloring a first region of the surface with a third color that is substantially the same as the first color and coloring a second region of the Surface adjacent said first region with a fourth color that is substantially the same as the second color. A third region is provided between the first region and the second region so that the third region contains the third color and the fourth color combined to form a color gradient such that there is a gradual transition from the third color in the first region to the fourth color in the second region.
In a second aspect, the present invention is directed to a method of camouflaging an exterior surface of a structure not intended for human occupancy, wherein the camouflaged structure is located between a vantage point and a background and a foreground extends away from the structure in a direction opposite the background. The method includes the steps of providing the exterior surface of the structure not intended for human occupancy with at least one reflector having a reflective surface and positioning the at least one reflector such that the reflective surface reflects light from a portion of the foreground to the vantage point.
In a third aspect, the present invention is directed to a method of camouflaging an exterior surface of a structure located between a vantage point and a generally uniform background, wherein a foreground extends away from the structure in a direction opposite the background. The method includes the steps of providing the exterior surface with at least one reflector having a reflective surface, filtering from light incident the at least one reflector at least one wavelength of visible light and positioning the at least one reflector such that the reflective surface reflects at least a portion of the filtered light to the vantage point.
In a fourth aspect, the present invention is directed to a method of camouflaging an exterior surface of a structure located between a vantage point and a generally uniform background, wherein a foreground extends away from the structure in a direction opposite the background. The method includes the steps of providing the exterior surface with at least one semi-diffuse reflector having a reflective surface and positioning the at least one semi-diffuse reflector such that the reflective surface reflects light from a portion of the foreground to the vantage point.
In a fifth aspect, the present invention is directed to a method of camouflaging an exterior surface of a structure located between a vantage point and a generally uniform background, wherein a foreground extends away from the structure in a direction opposite the background. The method includes the steps of capturing at a first region light from at least one of the generally uniform background and the foreground, conducting the light to a second region located proximal to the exterior surface and spaced from the first region and emitting the light at the second region such that at least a portion of the light is directed toward the vantage point without forming an image.
In a sixth aspect, the present invention is directed to a camouflaged structure located between a background and a vantage point, wherein the background contains a first color and a second color simultaneously or at different times. The camouflaged structure includes a member having a surface visible from the vantage point and further includes a pattern of colors applied to said surface. The pattern comprises a first region, a second region and a third region. The first region contains a third color that is substantially the same as the first color. The second region contains a fourth color that is substantially the same as the second color. The third region contains the third color and the fourth color combined to form a color gradient such that there is a gradual transition from the third color in the first region to the fourth color in the second region.
In a seventh aspect, the present invention is directed to a camouflaged structure not intended for human occupancy, wherein the camouflaged structure is located between a generally uniform background and a foreground containing visible light and a vantage point. The camouflaged structure includes a member having an exterior surface and a reflector having a reflective surface. The reflector is attached to the structure and located adjacent the exterior surface between the exterior surface and the vantage point and the reflective surface is positioned so that at least a portion of the visible light contained in the foreground is reflected to the vantage point.
In an eighth aspect, the present invention is directed to a camouflaged structure located between a generally uniform background and a foreground containing visible light and a vantage point. The camouflaged member includes a member having an exterior surface and a semi-diffuse reflector having a reflective surface comprising a plurality of light diffusing elements. The semi-diffuse reflector is attached to the structure and located adjacent the exterior surface and between the exterior surface and the vantage point, and the reflective surface is positioned so that at least a portion of the visible light contained in the foreground is reflected to the vantage point.
In a ninth aspect, the present invention is directed to a camouflaged structure located between a generally uniform background and a foreground, wherein the foreground contains visible light and a vantage point and has a generally uniform composition comprising characteristic wavelengths of visible light. The camouflaged structure includes a member having an exterior surface and a reflector having a reflective surface. The reflector is attached to the structure and is located adjacent the exterior surface and between the exterior surface and the vantage point. The reflective surface is positioned so that at least a portion of the visible light contained in the foreground is reflected to the vantage point. A filter is located between the vantage point and the reflective surface. The filter is for filtering at least one wavelength of visible light that is different from the characteristic wavelengths of visible light.
In a tenth aspect, the present invention is directed to a camouflaged structure located between a generally uniform background and a foreground containing visible light and a vantage point. The camouflaged structure comprises a member that includes an exterior surface having a camouflaged region. A camouflaging member is attached to the camouflaged structure. The camouflaging member comprises a light capturing feature, a light emitting feature and a light conductor. The light capturing feature is spaced from the camouflaged region and is provided for capturing light from at least one of the generally uniform background and the foreground. The light emitting feature is located proximal to the camouflaged region and is provided for emitting light captured by the light capturing feature toward the vantage point without forming an image. The light conductor extends between the light capturing feature and the light emitting feature and is provided for conducting light captured by the light capturing feature to the light emitting feature.
For the purpose of illustrating the invention, the drawings show a form of the invention that is presently preferred. However, it should be understood that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings.
Referring now to the drawings, wherein like numerals indicate like elements, there is shown in
The camouflaging techniques of the present invention are particularly suited for structures that are not intended to be occupied by humans and because of their size, shape and/or primary function, are generally difficult to visually integrate into their surroundings. Thus, although the invention is described with respect to cell tower 100, one skilled in the art will understand that the camouflaging techniques of the present invention may be used to reduce, or eliminate, the visibility of many other structures and/or components thereof such as power transmission support towers and cables, light posts, guy wires, chimneys, hyperbolic cooling towers, microwave communication towers, radio and television antennas and support towers, suspension and cable-stayed bridge support towers and cables and water towers, among others. Such structures primarily comprise functional components having unattractive non-specular visible surfaces. In addition, the camouflaging techniques of the present invention may be used to reduce, or eliminate, the visibility of structures against backgrounds other than the sky having uniform hues, saturation and brightness. Examples of other backgrounds include a sea, ocean or other body of water near the horizon and generally bright landscapes containing features such as snow and sand.
Cell tower 100 includes a vertical support 104, a plurality of antennas 106 and a plurality of antenna support brackets 108. Vertical support 104 comprises an elongate cylindrical tube 110 having a lower end 112 affixed to a foundation (not shown) and an upper end 114 located high above the foundation. Each antenna 106 is attached to tube 110 adjacent upper end 114 by one of brackets 108. Each antenna 106 may be any type of communications antenna such as an RF transceiver antenna for mobile communications devices, an RF transmitting antenna for radio, TV or the like or a microwave relay antenna for long distance transmission of signals, among others. The details of such antennas are not important to the invention and are know to those skilled in the art. Therefore, they are not discussed in detail herein. Each bracket 108 includes two horizontal members 116, a vertical member 118 and a diagonal member 120.
Cell tower 100 is merely illustrative of the many variations of cell towers possible. Other embodiments may include vertical supports of other tubular shapes, such as hexagonal, or other structures, such as latticed structures made from tubular members or other structural shapes. In addition, guy wires may be provided to stabilize the upper end of cell tower in the horizontal direction. One skilled in the art will recognize that there are many configurations of cell towers possible and, therefore, each configuration need not be described in detail herein.
Due to its height, cell tower 100 will generally be viewed as shown in
As used herein and in the claims appended hereto, the entirety of the sky surrounding cell tower may be considered to consist of two regions, a background sky 122, which is generally the portion of the sky that appears to viewer or is obscured by the cell tower or portion thereof when looking at the cell tower or portion thereof, and a foreground sky 124, which is generally the portion of the sky other than the background sky. Thus, depending on the location of vantage point 102 and the viewing direction, background sky 122 may include a region of the sky near the horizon, at the zenith and/or any region therebetween.
Referring now to
In its basic form, pattern 126 includes a first region 128, a second region 130 and a third region 132 located between the first and second regions. First and second regions 128, 130 are composed of, respectively, first and second predominant colors selected to exactly, or substantially, match two colors that predominate in background sky 122. Since the composition (hue, saturation and brightness) of background sky 122 changes throughout the day and with ambient weather conditions, the colors selected for first and second predominant colors are preferably two colors that predominate during the time of day and/or weather condition during which it is most desired to obscure antenna 106. Typically, the colors selected will be colors that predominate in daylight sky.
Since the composition of daylight sky varies over time and with location, first and second predominant colors can be selected to approximate the composition of background sky over a range of similar sky conditions. For example, when cell tower 100 is viewed from a vantage point where background sky 122 is the sky just above the horizon, first and second colors may be blue and white, since a cloudless blue sky contains more white at the horizon than at its zenith. The blue and white selected based on a cloudless sky would also be appropriate for a sky containing light clouds and blue regions interspersed with the lights clouds. The first and second predominant colors selected will generally be a compromise that provides a satisfactory appearance for the greatest amount of time. A preferred technique for selecting the colors for first and second regions 128, 130 is to view various combinations of a variety of colors against background sky 122 when the background sky has the composition at which antenna 106 is desired to be obscured.
Once first and second colors have been selected as described above and applied to the corresponding first and second regions 128,130 of pattern 126, third region 132 is created by transitioning the first color to the second color so that the third region contains a gradual color gradient from the first color at first region 128 to the second color at second region 130 using techniques known to those skilled in the art. A gradual color gradient is desired since the composition of background sky 122 will usually not includes sharp boundaries between regions of adjacent colors. Thus, the gradual gradient of third region 132 more precisely simulates the expected composition of background sky 122, causing pattern 126 to better obscure antenna 106. This approach differs from conventional camouflage techniques where a sharp transition line, rather than gradual color gradient, exists between adjacent color regions.
In an alternative embodiment wherein it is desired to reduce the visibility of antenna 106 over a larger range of compositions of background sky 122, a pattern 126′ of first, second and third regions 128′, 130′, 132′ may be provided as shown in
An important feature of pattern 126′ is the location of first and second regions 128′, 130′ with respect to one another and with respect to the edges 134 of antenna 106′. First and second regions 128′, 130′ alternate with one another in generally close proximity to one another, with third region 132′ located between adjacent first and second regions 128′, 130′, along each edge 134. Thus, when the composition of background sky 122 contains the first composition, there is a good match between first region 128′ and the background sky, obscuring edges 134 at the first regions. Similarly, when the composition of background sky 122 contains the second composition there is a good match between second region 130′ and the background sky, obscuring edges 134 at the second regions. At compositions of background sky 122 intermediate the first and second compositions, there would be an acceptable match with both first and second regions 128′, 130′ and a good match with third region 132′, obscuring edges 134 at the third region. Preferably, first and second regions 128′, 130′ are spaced from one another and sized such that at an expected vantage point the brain of a viewer will average the regions of pattern 126′ of good color match to background sky 122 and the background sky adjacent those regions such that the other regions of the pattern 126′ appear obscured to the viewer. For example, at an optimal spacing, if first regions 128′ match the composition of background sky 122, then the brain of the viewer will average the color of first regions 128′ and the adjacent color of the background sky to render second regions 130′, at least the second regions at edges 134, obscured.
It is noted that patterns 126, 126′ shown in
Referring again to
Referring now to
Reflector 140 includes a reflective surface 146 facing vantage point 102′. Preferably, reflective surface 146 has a substantially constant reflectance across the spectrum of visible light such that the hue, saturation and brightness of the reflected light closely matches the hue, saturation and brightness, or composition of the incident light. In this manner, the reflected light will most closely match the hue, saturation and brightness of the light in background sky 122. The embodiment of
Reflector 140 may optionally include a transparent layer 148 made of, e.g., acrylic, glass or other material, that covers reflective surface 146. Transparent layer 148 may serve at least two functions. First, transparent layer 148 may be provided as a protective layer for protecting reflective surface 146 from damage due to environmental elements. Second, transparent layer 148 may be provided as a filter to prevent reflector 140 from reflecting one or more wavelengths of unwanted light to a viewer. Accordingly, transparent layer 148 may be provided with one or more organic dyes and/or inorganic compounds that absorb one or more wavelengths of visible light desired to be removed from the light incident to reflector 140. Generally, the wavelengths desired to be absorbed are primarily in the range of green through red light. However, for certain applications it may be desired to remove other visible wavelengths such as yellow. For example, if foreground sky 124 contains the sun and it is desired to remove the orange and red components of the sunlight incident to reflector 140, certain dyes may be added to remove these components. Appropriate dyes for removing unwanted wavelengths are known to those skilled in the art and, therefore, are not enumerated herein. In some instances, e.g., when background sky 122 is the horizon and foreground sky 124 is a cloudless blue daylight sky, it is advantageous to not remove all of the yellow component of sunlight. Yellow is the complement of blue, and thus in this example would add whiteness to the reflected portion of blue foreground sky 124 to more closely match blue-white background sky 122 on the horizon.
Alternatively to providing a specular reflector as illustrated in
Semi-diffuse reflector 150 includes a plurality of convex spherical segments 152 on which reflective surface 154 is formed. The included half-angle (½ θ) of each spherical segment 152 preferably should not be much larger that the expected minimum angle between a horizontal plane bisecting the spherical segment and a line extending through the center of curvature C of the spherical segment and vantage point 102″ of a viewer. The dimensions of convex spherical segments 152 in the direction along reflective surface 154 and the distance between adjacent segments 152 (pitch) P may be any value down to about one micron.
Reflective surface 154 collects, and thus averages when viewed from a great distance, light over a solid angle of 4θ steradians, where θ (in radians) is the included angle of spherical segment 152. For example, if θ=B/9 (20°) the light reflected from ambient sky near the reflector axis to vantage point 102″ a great distance from reflective surface would be gathered from 4B/9 steradians. Any semi-diffuse reflector, including an ideal “cosine” reflector, that reflects up to 100% of the light incident to it is considered to be within the scope of the present invention.
The brightness of the sun is, of course, many times brighter than the brightest sky. Collecting light from a larger portion of foreground sky 124 attenuates the effect of the brightness of the reflected sun in approximate proportion to the ratio of the subtended solid angle of the sun to the subtended solid angle of the reflected (viewed) portion of the foreground sky. Since the included angle of the sun as viewed from the surface of the earth is about 0.55°, when each spherical segment 152 has an included angle of 30°, the ratio of the subtended solid angle of the sun to the subtended solid angle of the reflected portion of foreground sky 124 is approximately 6×10−5. Thus, the brightness of the sun when the sun is in the reflected portion of foreground sky 124 is highly attenuated. An additional attenuation of apparent brightness of the sun of approximately 10 to 15 times that achieved by diffusion can be obtained by providing a transparent layer (not shown), discussed above, covering reflective surface 154 and containing one or more appropriate dyes that remove a substantial portion of the light of wavelengths longer than about 490 nm contained in the sunlight incident to the reflective surface.
Surface feature 160 is similar to surface feature 158 except that it forms a recess in reflective surface 154′. Similar to surface feature 158, surface feature 160 may be any length desired. Surface feature 162 protrudes from reflective surface 154′ and contains a multifaceted reflective surface 169. The size, shape and number of facets on multifaceted reflective surface 169 may be any desired to suit a particular application. Surface feature 164 is similar to surface feature 162 except that it forms a recess in reflective surface 154′. Similar to surface feature 162, surface feature 164 may include any size, shape and number of facets desired to suit a particular application.
Each surface feature 156, 158, 160, 162, 164 may be used separately or in combination with other surface features. One skilled in the art will recognize that the surface features shown are merely illustrative of the many surface features shapes possible. One skilled in the art will also recognize that certain shapes may be more desirable in some applications than in others and that selection of surface feature shapes is dependent upon variables such as the compositions of foreground sky 124 and background sky 122 during which the camouflage is desired to be most effective and the size, shape and orientation of the component of the structure camouflaged with this aspect of the present invention. In addition, the semi-diffuse properties of reflector 150 may be provided by incorporating a flake-type pigment, such as an aluminum flake pigment, into an otherwise transparent layer (not shown).
Referring now to
Referring again to
Referring now to
Conductor 176 includes a reflective surface 182 adjacent the outer surface of horizontal member 116 and plurality of light capturing/emitting features 184, 186 that aid in capturing light and/or emitting light rays conducted through transparent layer 178. Since light may travel in either direction along a particular path traced by a ray, a light capturing feature for a light ray traveling in one direction is a light emitting feature for a light ray traveling in the opposite direction. It is noted that reflective surface 182 need not be provided. However, providing reflective surface 182 generally improves the performance of camouflaging member 174 when the camouflaging member functions in accordance with the second aspect described above. As described in more detail below, light capturing/emitting features 184, 186 may be designed to capture incident light from particular regions of the background sky 122 and/or foreground sky 124 and emit the captured light toward the expected vantage point(s).
Depending on the location of an object (not shown), such as the sun, that emits and/or reflects light that contrast sharply in hue and/or brightness with the light in background sky 122, transparent layer 178 may include one or more certain dyes, as described above, to remove unwanted wavelengths of light before the light is emitted from camouflaging member 174.
To illustrate the optical characteristics of camouflaging member 174, a light source 187 emitting three generally parallel light rays 188, 190, 192 are shown. Rays 188, 192, enter transparent layer 178 and strike reflective surface 182 at an angle less than the angle of internal reflection of the transparent layer. Therefore, reflective surface 182 reflects rays 188, 192 out of transparent layer. Ray 190, however, is directed by light capturing/emitting feature 184 into transparent layer 178 so that its reflected angle is greater than the angle of internal reflection of the transparent layer. Thus, ray 190 is conducted through transparent layer 178 until it strikes emitting feature 186, which directs the ray out of the transparent layer preferably toward an expected vantage point.
Camouflaging members 210, 210′, 210″ of
Microspheres 230 are of different sizes and are distributed generally randomly throughout center layer 224. However, in alternative embodiments, microspheres 230 may all be of the same size and/or may be distributed uniformly or non-uniformly in center layer 224, depending upon the requirements of a particular design. Microspheres 230 are preferably gas bubbles, such as air bubbles, formed within center layer 224 during its manufacture. However, microspheres 230 may be another structure, such as beads of a solid material, that were, e.g., added to center layer during its manufacture. Although microspheres 230 are illustrated, one skilled in the art will recognize that other reflective and/or refractive features of regular and/or irregular geometric shapes may be provided. Such features may be oriented within center layer uniformly, non-uniformly or randomly.
Camouflaging member 222 may optionally include a reflective surface 238 located adjacent the outer surface of the structure (not shown) desired to be rendered less visible using the present invention. Reflective surface 238 is provided to reflect light rays not otherwise conducted by internal reflection within center layer 224 to aid in brightening camouflaging member 222 so that it more closely matches the brightness of the background sky. Reflective surface 238 may be provided on the outer surface of the structure or may be formed by metalizing the outer surface of boundary layer 228 using a method known in the art. Preferably, reflective surface forms a semi-diffuse reflector, as described above. However, reflective surface 238 may also be specular.
Referring now to
An increase in light capturing efficiency may be obtained in a preferred direction when light capturing/emitting features 242 are not symmetrical about a horizontal axis as shown, but rather are skewed so as to present a greater surface toward the preferred direction. An embodiment illustrating this feature is shown in
Referring now to
When light impinges upon camouflaging member 292 from above, upper surface 296 of conductor functions as the light capturing feature that directs light rays into the conductor. Correspondingly, lower surface (not shown) of conductor functions as the light emitting feature that directs light rays to an expected vantage point located below camouflaging member 292. Conversely, when light impinges upon camouflaging member 292 from below, the lower surface functions as the light capturing feature and upper surface 296 functions as the light emitting feature that directs light rays to an expected vantage point located above the camouflaging member. Upper surface 296 and the lower surface may be parallel to one another or they may be skewed in any direction, depending upon the particular design parameters.
One or both of upper surface 296 and the lower surface optionally may include surface features (not shown), such as convex spherical protrusions and pyramid-shaped protrusions, that diffuse and/or direct the light rays entering or exiting camouflaging member. In
Preferably, as shown in
Although the various aspects of the present invention have been described in connection with particular components of cell tower of
While the present invention has been described in connection with preferred embodiments, it will be understood that it is not so limited. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1305296||Jun 3, 1919||Kwotss op bendebjng objects less visible against backgrounds|
|US2292848||Mar 11, 1942||Aug 11, 1942||Standard Varnish Works||Camouflage|
|US2398620||Jun 5, 1944||Apr 16, 1946||Gen Electric||Apparatus for reducing the visibility of an object silhouetted against the sky|
|US3576563 *||May 20, 1968||Apr 27, 1971||Railroad Accessories Corp||Railroad signal having light piping from source mounted an exterior of reflector cone|
|US4087159||Sep 19, 1975||May 2, 1978||Max-Planck-Gesellschaft Zur Forderung Der Wissenschaften E.V.||Self imaging system using a waveguide|
|US4192576||Nov 20, 1978||Mar 11, 1980||Minnesota Mining And Manufacturing Company||Ultra-high-index glass microspheres and products made therefrom|
|US4256366||Apr 9, 1979||Mar 17, 1981||Buckelew Arthur L||Aircraft visual collision and avoidance device|
|US4299442||Apr 14, 1980||Nov 10, 1981||Buckelew Arthur L||Aircraft visual collision and avoidance device|
|US4347284||Nov 3, 1980||Aug 31, 1982||Hiraoka & Co., Ltd.||White cover sheet material capable of reflecting ultraviolet rays|
|US4465731||Jun 27, 1983||Aug 14, 1984||Gunter Pusch||Universal camouflage for military objects|
|US4506467||May 12, 1983||Mar 26, 1985||Norman Strung||Portable mirror blind|
|US4560595||Mar 22, 1984||Dec 24, 1985||Diab-Barracuda Ab||Thermal/optical camouflage with controlled heat emission|
|US4560608||Jun 20, 1984||Dec 24, 1985||Gunter Pusch||Winter camouflage material|
|US4611524||Aug 20, 1984||Sep 16, 1986||Ferris Carlisle K||Camouflaged vehicle such as an aircraft, surface vessel or the like|
|US4868019||May 2, 1988||Sep 19, 1989||Knickerbocker Harry W||Camouflage system and material|
|US4953922||Aug 21, 1987||Sep 4, 1990||Hb Radicool Research & Development||Web material for camouflage against electromagnetic radiation|
|US5027566||Apr 12, 1990||Jul 2, 1991||Gilowski John P||Window with reflective enclosure|
|US5043202||Dec 29, 1989||Aug 27, 1991||Chameleon Camouflage System, Inc.||Camouflage system and material using three reflective levels|
|US5122657 *||Sep 12, 1990||Jun 16, 1992||U.S. Philips Corp.||Anti-reflection arrangement for optical document scanner|
|US5142833||Mar 7, 1991||Sep 1, 1992||Svehaug Oswald C||Camouflage screen|
|US5220631||Dec 23, 1991||Jun 15, 1993||Grippin Raymond R||Fiber optic camouflage|
|US5347435 *||Dec 22, 1992||Sep 13, 1994||Hughes Aircraft Company||Linear lamp holographic trapped beam center high mounted stoplight|
|US5373863||Dec 29, 1992||Dec 20, 1994||Prizio; Ricci||Invisi-blind camouflage device|
|US5418582 *||Oct 15, 1993||May 23, 1995||Lions Eye Institute Perth||Photokeratoscope apparatus and method|
|US5540978||May 11, 1994||Jul 30, 1996||The Dow Chemical Compny||All-polymeric ultraviolet light reflecting film|
|US5592960||Nov 1, 1995||Jan 14, 1997||Williams; Christopher R.||Hunting blind|
|US5617692||Feb 14, 1994||Apr 8, 1997||Ebert Composites Corporation||Composite structure|
|US5674605||Sep 15, 1995||Oct 7, 1997||Minnesota Mining And Manufacturing Company||Retroreflective transfer sheet and applique|
|US5846614||Jun 30, 1997||Dec 8, 1998||Conner; Kyle Henry||Methods for increasing a camouflaging effect and articles so produced|
|US5852424||May 20, 1997||Dec 22, 1998||Stealth Network Technologies Inc.||Building elements and support structure for enclosing an antenna|
|US5985381||Nov 27, 1998||Nov 16, 1999||Conner; Kyle Henry||Methods for increasing a camouflaging effect and articles so produced|
|US5991048 *||Oct 25, 1996||Nov 23, 1999||University Of Washington||Surface plasmon resonance light pipe sensor|
|US6032070 *||Jun 7, 1995||Feb 29, 2000||University Of Arkansas||Method and apparatus for detecting electro-magnetic reflection from biological tissue|
|US6040881||Jul 16, 1997||Mar 21, 2000||Canon Kk||Projection type display apparatus with color optimized anti-reflection films|
|US6061828||Mar 21, 1997||May 16, 2000||Josephs; Ira||Camouflage items and camouflage material thereon|
|US6163400||Jul 15, 1997||Dec 19, 2000||Canon Kabushiki Kaisha||Variable magnification optical system and image pickup apparatus using the same|
|US6278847||Feb 25, 1999||Aug 21, 2001||California Institute Of Technology||Aperture coded camera for three dimensional imaging|
|USD426128||May 5, 1999||Jun 6, 2000||General Housewares Corporation||Hammer|
|U.S. Classification||52/311.1, 359/850, 359/853, 359/856, 359/838|
|International Classification||B44F9/00, B44F7/00, F41H3/00|
|Cooperative Classification||H01Q1/44, H01Q1/1242, G02B6/0016, F41H3/00, G02B6/0038|
|European Classification||H01Q1/44, H01Q1/12D, G02B6/00L6O4G, G02B6/00L6I4G, F41H3/00|
|Nov 10, 2010||FPAY||Fee payment|
Year of fee payment: 4
|Dec 24, 2014||REMI||Maintenance fee reminder mailed|
|May 15, 2015||LAPS||Lapse for failure to pay maintenance fees|
|Jul 7, 2015||FP||Expired due to failure to pay maintenance fee|
Effective date: 20150515